This application is based upon and claims the benefit of priority from the prior Japanese Patent applications No. 9-258552, filed Sep. 24, 1997; and No. 10-264342, filed Sep. 18, 1998, the entire contents of which are incorporated herein by reference.
The present invention relates to an apparatus for inspecting defects in a substrate such as a glass substrate for a liquid crystal display (LCD).
Of conventionally-known apparatuses for inspecting defects of LCD glass substrates, some apparatuses are known in which defects (e.g., scratch) formed in the surface of the glass substrate can be checked by using a macro observation and a micro observation interchangeably. In the macro observation, light is applied onto the surface of the glass substrate and then optical change of the reflected light is observed, thereby detecting the defects. In the micro observation, the defects found by the macro observation are magnified and observed.
For example, Jpn. Pat. Appln. KOKAI No. 5-322783 employs the macro observation system and the micro observation system which are set so as to correspond to an X-Y stage designed movable horizontally in X and Y directions. In the apparatus, the macro observation or the micro observation is performed by mounting a substrate on the X-Y stage and bringing a portion of the substrate to be inspected (defect) into an observation filed of the macro observation system or the micro observation system by moving the X-Y stage two-dimensionally in the X and Y directions.
Recently, the size of the glass substrate tends to be increased with an enlargement of LCD. In the case where such a large glass substrate is inspected by using the inspecting apparatus having the X-Y stage which is movable horizontally and two-dimensionally (X, Y directions), four times as large as the area of the glass substrate is required as a space for moving the X-Y stage. Therefore, the substrate inspecting apparatus is inevitably large with the increase of the glass substrate.
Furthermore, in the conventional inspection apparatus thus constructed, it is difficult to inspect a small scratch since the surface of the substrate is far away from an eye position of the inspector. Moreover, it is difficult to obtain positional data of the defect found in the surface of the substrate. Accordingly, it has been impossible to inspect the substrate highly accurately.
An object of the present invention is to provide an substrate inspecting apparatus capable of detecting a defect of the substrate efficiently with high accuracy as well as to provide the apparatus in a reduced size.
The substrate inspecting apparatus of the present invention comprises substrate holding member for holding a substrate to be inspected, a driving mechanism for raising the substrate holding member to a predetermined angle or less, a position coordinate detecting section provided at side edge of the substrate in at least two directions, for detecting coordinates of a defect present in the substrate, an observation system supporting section provided for supporting a micro observation system and moving on the surface of the substrate, and a controlling section for controlling of the movement of the micro observation system of the observation system supporting section to correspond to a defect formed present in the substrate, on the basis of the position coordinates of the defect detected by the position coordinate detecting section.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.